Bicycle with key-operated locking mechanism

Abstract

A bicycle with a key-operated locking mechanism for securing the steering connection between the handlebar and the front wheel fork to the frame to disable the bicycle. A lock cylinder in a protective housing is mounted on the rear side of the head tube of the frame, in the "V" of the frame struts, and has a lock body with an arcuate recess in which the fork stem is nested, and has a radial bolt that swings in an annular groove in the lock body, between a retracted, unlocking position and a forwardly extended, locking position in which the bolt projects into the recess and into one of two angularly spaced longitudinal locking slots in the telescoped fork and handlebar stems, thereby to prevent steering.

I claim as my invention: 
     
       1. In combination with a bicycle having a frame including an upright head tube having an opening in its rear side and two struts arranged in a "V" with the head tube at the vertex, a handlebar having a depending stem projecting downwardly into the head tube, a front wheel fork having an upstanding fork stem projecting upwardly into the head tube and telescoping with the handlebar stem, and means for rotatably mounting the telescoped stems in the head tube for steering of the bicycle, an improved locking mechanism fitted into the "V" between the struts and against the head tube, comprising: a cylinder lock extending transversely across said rear side and having a lock cylinder with a key slot at one end, a body rotatably supporting said lock cylinder and having an annular groove around the body, a removable key for turning said cylinder in said body between locking and unlocking positions, and a locking bolt mounted on said lock cylinder and extending radially therefrom into said groove to swing along the groove as the lock cylinder is turned by said key;   said body having an arcuate recess in its front side in which said stems are nested, and said bolt projecting forwardly into said recess and into said head tube when said cylinder is in said locking position, and being retracted from said recess when the cylinder is in the unlocking position;   means defining first and second angularly spaced, longitudinally extending locking slots in at least the outer one of said telescoping stems alongside said cylinder lock, to be aligned with said bolt in two selected angular positions of said handlebar and said front wheel fork, said locking slots being sized to receive said bolt with a relatively close locking fit and to prevent steering of the bicycle;   and a part-cylindrical protective lock housing fitted over said lock cylinder and having an opening exposing said one end, said lock housing being secured to said frame to hold and protect said cylinder lock.   
     
     
       2. In combination with a bicycle having a frame including a head tube, a handlebar assembly, a front wheel fork assembly, a steering connection between said assemblies in said head tube, and means rotatably supporting said assemblies on said head tube for steering of the bicycle, an improved locking mechanism, comprising: a cylinder lock mounted on said head tube alongside said steering connection and having a lock cylinder, two spaced, generally cylindrical heads forming a lock body with an annular groove between its ends, said body rotatably supporting said lock cylinder for rotation between locking and unlocking positions and having a recess on one side in which part of said steering connection is fitted, a key for turning said lock cylinder between said locking and unlocking positions, a radial locking bolt on said cylinder, said bolt being disposed in said groove to be projected toward said steering connection in said locking position and retracted therefrom in the unlocking position;   means forming opposed locking abutments on said steering connection for receiving the projecting locking bolt when said cylinder is in said locking position, thereby to prevent steering of the bicycle;   and a protective housing mounting said cylinder lock on said frame.   
     
     
       3. The combination of a bicycle and a locking mechanism as defined in claim 2 wherein said frame has two struts arranged in a "V" with said head tube at the vertex of the "V", and said protective housing is secured to said head tube and said struts in the "V". 
     
     
       4. In combination with a bicycle having a frame including a head tube and two struts arranged in a "V" with said head tube at the vertex of the "V", a handlebar assembly, a front wheel fork assembly, a steering connection between said assemblies in said head tube, and means rotatably supporting said assemblies on said head tube for steering of the bicycle, an improved locking mechanism, comprising: a cylinder lock mounted on said head tube alongside said steering connection and having a lock cylinder, means rotatably supporting said lock cylinder for rotation between locking and unlocking positions, a key for turning said lock cylinder between said positions, a radial locking bolt on said cylinder projecting toward said steering connection in said locking position and retracted therefrom in the unlocking position;   means forming opposed locking abutments on said steering connection for receiving the projecting locking bolt when said cylinder is in said locking position, thereby to prevent steering of the bicycle; and   a protective housing mounting said cylinder lock on said frame in the "V" between the struts and against said head tube.   
     
     
       5. The combination of a bicycle and a locking mechanism as defined in claim 4 wherein said means rotatably supporting said lock cylinder includes two spaced, generally cylindrical heads forming a lock body with an annular groove between its ends, said body having a recess on one side in which part of said steering connection is fitted, and said bolt being disposed in said groove to swing therein as the cylinder turns.